1. Field of the Invention
This invention relates to a flexibly foldable arm suitable for application as a robot arm or finger, and more particularly to a flexible arm which can be positively folded around an object of an arbitrary form to wrappingly grip the same.
2. Description of the Prior Art
It has thus far been known in the art to provide a flexible arm consisting of a plural number of link plates which are connected pivotally by pins and flexibly foldable by transmitting drive force through wires which are successively fitted around pulleys at the respective joints as described, for example, in Japanese Patent Publication No. 55-13874. The flexible arms of this sort, in which the arm operating force is transmitted by wires and pulleys, is advantageously simple in the construction of the drive system as compared with the arms with a rotational drive actuator at each joint. However, since the conventional drive systems are arranged to fold the link plates successively around an aimed object when part of the link plates comes into contact with the latter, it is difficult to flex an arm freely into a desired shape, for instance, into a C-shape or S-shape and to stretch out an arm to evade an obstacle irrespective of existence of an object to be gripped.